A peek inside Apple's A6 processor

SAN FRANCISCO—Apple Inc.'s A6—the processor powering its new iPhone 5—is likely fabricated by South Korea's Samsung Electronics Co. Ltd. and may employ ARM's "big-little" graphics processor core scheme, according to a preliminary teardown of the handset done by UBM TechInsights.

Samsung was widely considered the favorite to build the processor for Apple, just as the company has done for previous generations, the A4 and A5. But tensions in the courtroom and elsewhere between the two companies in recent times led to speculation that Taiwan Semiconductor Manufacturing Co. Ltd. (TSMC) might displace the incumbent this time around.

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The teardown analysis by UBM TechInsights concluded that the A6 die shrink of 95.04 mm2 is much smaller than the 162.54 mm2 of the Apple A5X processor and the 45-nm version of the A5 processor, which was also a large 122.21 mm2.

Apple A6 die photo (click on image to enlarge).

A detailed look at the de-caped A6 by UBM TechInsights revealed that only three of the processors graphics cores are easily identifiable.

Allan Yogasingam, a technical research manager at UBM TechInsights, said Apple may have employed ARM's so called "big-little" technique, which involves pairing a high-performance processor core and a power-efficiency tuned processor core to share processing duties in a cache-coherent combination, yielding overall power savings.

"Apple may have used a 'big-little' approach and gone with either a flexible fourth core or a smaller one," Yogasingam said. "Either way, it’s a very unique processor design which was expected from Apple’s custom approach to it."

A diffusion image of the A6 processor shows the location of the ARM cores and other elements (click on image to enlarge).

Source: UBM TechInsights

UBM TechInsights is owned by UBM plc, the same company that publishes EE Times.

There's nothing "big-LITTLE" about a couple identical CPUs and a trip of graphics cores. Big-LITTLE is about a smaller CPU (maybe Cortex-A7) to offload a larger CPU (-A15). While big-LITTLE would be a good approach, I'm not sure I've seen any indication that was done in this chip. Separate on-chip graphics cores are standard design practice.